The Tiffen Black Diffusion/FX 4 6.6 x 6.6" filter diffuses strong light entering the lens and produces a halo effect. Although the resulting image appears softer and more ethereal, there is little loss of clarity or detail. This filter works by diffusing light entering the lens with small aberrations; by distributing light more evenly, a soft halo is created rather than the sharp, well-defined image obtained without a filter. Density 4 offers more softening than 3, but less than 5.nnTiffen filters are manufactured using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and polishing it flat to a tolerance of 1/10,000th of an inch. This filter measures 6.6 x 6.6" / 167.6 x 167.6 mm.nnn- The diffusion filter gives photographs an ethereal quality, creating a dreamlike atmosphere.n- The soft image quality does not compromise the overall detail of the image.n- Light entering the lens is diffused by small aberrations, creating a soft halo rather than the sharp, well-defined image obtained without a filter.nnnSpecificationn